Telecommunication is effected with cellular telephony base station transmit-receive systems by (a) transmission signals propagated through space from the station and occupying a wide-band of frequencies and (b) reception signals propagated through space to the station and occupying a wide-band of frequencies different from that occupied by the wide-band transmission signals. Both the wideband transmission signal and the wide-band reception signal are subdivided into the same number X of smaller frequency bands which, although different in frequency, respectively correspond to each other one-to-one, and which respectively provide for the system X channels for the conversation. In the use of the system, the smaller frequency "channel" bands in, respectively, the wide-band transmission and reception signals and corresponding to only one channel are occupied from time to time by, respectively, transmission channel signals and reception channel signals for that one channel.
In the case of wide-band reception signals, those signals may be of two kinds, namely, main wide-band reception signals, and diversity wide-band reception signals received by, respectively, a main antenna and a diversity antenna for the base station system. Both such main and diversity wide-band reception signals occupy the same wide frequency bands and differ from each other only in respect of the antennas by which they are received.
To restate the above, a base-station transmit-receive system utilizes X channels of which each channel is different in the frequency bands employed therefor from any other of such X channels, each of the X channels being provided by (a) a channel frequency band therefor within the wide-band transmission signal, (b) a different channel frequency band therefor within the wide-band main reception signal, and (c) another channel frequency band therefor (the same in frequency as the mentioned channel band within the wide-band main reception signal) which is within a wide-band diversity reception signal in the event the system provides for diversity reception. As indicated above, "transmission channel signals" and "receiver channel signals" are signals which are contained within particular respective channel bands, and which convey conversations to be transmitted and received, respectively, by the base station. There may be two species of receiver channel signals, namely, "main receiver channels" and "diversity receiver channel signals".
A common past arrangement for the channel signal processing circuits in a base station transmit-receive system has been for all the channel signal processing circuits for each particular channel to be packaged within a common housing respective to that channel. Specifically, the transmitter circuit which produces the transmitter channel signals for "ith" channel is packaged within the same housing as the receiver circuit which processes the main receiver channel signals for that "ith" channel and, if there is diversity reception, the same housing also includes the receiver circuit which processes the diversity receiver channel signal for the "ith" channel. Such packaging in the same housing of all the channel processing circuits for each provided channel leads, however, to the required use of a large number of coaxial cables extending between the totality of such circuits in the system and the further signal conveying circuits intervening those channel frequency processing circuits and the antenna or antennas of the system. For example, if the system has 24 channels, 48 of such cables are needed if the system has no diversity reception, and 72 of such cables are needed if the system employs for reception both a main antenna and a diversity antenna. The need for the base station transmit-receive system to use such a large number of coaxial cables has, however, the disadvantages that the cost of such cables is high and the lay out of such cables becomes complicated and occupies much space.